IMO this has always been a nonsense argument. If someone is too mentally deficient to live among normal humans without killing them, then they should not be on Earth.
Welcome to our dysfunctional legal system. *IT* is mentally deficient, and this is but one more example.
One of my favorite examples of the irrational screwy logic it uses, is the Alec Baldwin case. The idiot Judge decided that because the Prosecution didn't give the Defense irrelevant ballistic data, Alec Baldwin should go free.
He *KILLED* someone, and the New Mexico prosecution may have intentionally (to throw the case on purpose) or inadvertently, failed to give absolutely useless data to the Defense, which I believe they didn't even ask for.
So the Judge lets the murderer go, *AND* she lets the incompetent/complicit Prosecutor go.
Two bad deeds and nobody gets punished!
Actually, that's wrong. The people of New Mexico get punished!
Somehow, in the legal system, two bad deeds cancel out.
Worst possible result for the entire country, and that is the default result in this sort of circumstance.
The logic is sound...